An Overview

The microphone is actually a fairly simple device, conceptually. It consists of a very delicate diaphragm suspended in air that moves back and forth due to air pressure changes (sound waves). That diaphragm is connected to one of several different electromagnetic mechanisms that converts the motion of the diaphragm to an alternating electrical current. That current flows in a cable connected to the mixing console, and becomes the basis for the audio signal that we will process, record, and ultimately send to a loudspeaker, where it will be converted back to sound. The process can be described in a fairly straightforward way: waves of air pressure buffet the diaphragm, which moves back and forth as a result. That motion is converted into an equivalent electrical motion. Voila! Audio is created!

The ear, on the other hand, is a very complicated device conceptually. It consists of a very delicate diaphragm suspended in air that moves back and forth due to air pressure changes (sound waves). That diaphragm is connected, via a fairly elaborate mechanical linkage, to a remarkable organ called the basilar membrane. At the basilar membrane, the mechanical motions are converted to neurological impulses that are sent to our brain. There, along with some other things, those impulses are presented to our conscious mind. Voila! We hear sound!

In a rudimentary way, then, the microphone converts sound into an analogous electrical waveform, while the ear converts it into neurological impulses. So what's the big deal? How does that difference affect our approach to the recording process?

The first thing you've got to understand might be called the paradox of perception: what we hear is not what comes in our ears. What we consciously hear is an extremely highly edited, polished, rewritten, equalized, compressed, noise-reduced, vocoded, positive-feedback-looped, delayed, stereo-enhanced, reorganized, remixed, mastered, converted to digital pulse-code construction that has very little relationship to the raw physical sound data that went into our ears.

A couple of years ago I had a medical misadventure which required that, for diagnostic testing, I take an anti-convulsant drug that was also, incidentally, psychoactive (which is high-tech slang for "mind-bending"). One of the systems it affected was the auditory system -- it tended to inhibit outbound neurological impulses sent from the auditory cortex in the brain to the basilar membrane in each ear. The result was a dramatic change in the amount of signal-processing that occurred to the inbound impulses of auditory data en route to my poor, confused brain. I noticed differences particularly in noise-based sounds. The hissing, rushing sound of a shower, for instance, turned into a rough, industrial-strength crackling, almost like a wood fire. Musical sounds seemed rough, poorly defined, and with very clangorous, ambiguous pitch. It was weird there, for a couple of days. And the insight I gained, after asking the doctor just what the fuck he was giving me (the drug makes you a little violent, too!) and was it really supposed to destroy my hearing (dark thoughts of malpractice suits zinging away through what remained of my nervous system!), was that what I have come to expect music to sound like isn't really what comes in my ears. My own auditory mechanism, when it isn't ripped out of its gourd (another high-tech expression for "a little confused right now"), adds a lot, an awful lot, to the process.

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